Industrial effluents generated by chemical, textile, metal-processing, and mining industries contain complex mixtures of diverse pollutants. These contaminants include persistent organic pollutants, recalcitrant organic compounds, and toxic heavy metals. These contaminants, either individually or through synergistic interactions, can adversely affect ecosystems and human health. Their coexistence can enhance wastewater treatment resistance and reduce the effectiveness of conventional processes, including activated sludge, coagulation–flocculation, and adsorption-based treatments. Therefore, developing efficient processes capable of simultaneously removing diverse contaminants remains a major challenge in environmental engineering.
Porous polymeric foams have recently attracted considerable attention as multifunctional adsorbent platforms. These materials are attractive due to their interconnected three-dimensional structures, low density, and high specific surface areas. Furthermore, their tunable surface chemistry and potential reusability can significantly enhance adsorption performance. These foams, particularly after surface modification or incorporation of active components, can enable simultaneous and selective removal of organic and inorganic contaminants. Moreover, recyclability and the incorporation of bio-based polymer matrices in some systems offer additional advantages in terms of environmental sustainability. In this review, polymeric foams are classified according to the origin of their polymer matrices (synthetic and bio-based foams) and their functional design strategies, including nanocomposite, smart, polymer–metal, and multilayer architectures. Furthermore, surface modification strategies, including functionalization, nanoparticle incorporation, and smart coating approaches, are discussed to enhance adsorption performance. These strategies aim to improve adsorption capacity, selectivity, and practical applicability in environmental remediation.
The primary adsorption mechanisms and the effects of operational parameters on foam performance are also evaluated. Recent studies indicate that modified foams, owing to their enhanced adsorption capacity and potential regeneration capability, may serve as complementary alternatives to conventional adsorbents under specific operating conditions. However, challenges related to production costs, scalability, and large-scale industrial implementation remain unresolved. Finally, the development of bio-based multifunctional foams for continuous-flow treatment systems is highlighted as an important direction for future research.